Power mechanism



POWER MECHANISM Filed SeptA 24, 1924 S 13 l] 33 O D O I a v 1 '31 1034 35 i, 26 30 lm'mlr:

Patented oct. 12, 192s.

.UNITED STATES Fmtrmr. nonsEY, or nocnns'rnn., NEWy YORK,

MENTS, To NORTH EAST ArrLmNcEs, INC., or

PORATION 0F NEW YORK.

PATENT OFFICE.

ASSIGNOR, BY MESNE.ASS1GN ROCHESTER, NEW YORK, A COR- rownn MEcHAnsm.

Application nled September 'Ihis invention relates to power mechanism suitable 'for use in operating the type-bars' or other members of a typewriter or Similar machine.

The object of the inventionis to produce mechanism, for the purpose in question, which shall be rapid and reliable in operation, andin which the parts shall be few in vnumber and simple and inexpensive in form.

It has been proposed to use power mechanism in which a rotary cam is jonrnaled on a lever and arranged to Swing the leverby engagement with a constantly rotatlng power-roller, the cam being thrown into engagement with the roller by a s ring, and its engagement being controlled y a keyactuated escapement. The present construction is generally similar in its mode of operation, but a feature of the invention resides in the fact that the cam does not rotate, but merely oscillates, and that it is moved positively into engagement with the power-roller by the operation of the key, while its return movement is accomplished by a spring; Other features of the invention will be set forth hereinafter in a description of the illustrated embodiment of the invention. In the accompanying drawin Fig.' l is a side-elevation of power ,mec anism embodying the present invention vas applied to a typewriter. Fig. 2 isa right-hand-end elevation of part of the mechanism shown in Fig. 1; and Fig. 3 is a side-elevation of certain parts of the mechanism, showing ihem in a different position from that of 'lghe invention is illustrated as embodied in mechanism in which a roller 5, covered with-rubber or other suitable frictional material, is constantly rotated from any source of power. This roller co-operates with two serles of cams 6 and 7, located respectively in front and inthe rear of the roller. Only one cam of each series is shown in the draw-v ings. The cams 6-and 7 are journaled in cam-levers 8 and 9 mounted on stationary pivot-rods 10. These cam-levers have hori-l zontal arms, 11 and 12 respectively, which are connected, by links 13 and 14, with respective bell-cranks 15 pivoted on a stationary rod 16. The bell-cranks are articulated with the type-bars 17 of the typewriter, in a well known manner, so that when the bellto ywhich is pivoted 24, 1924. Serial m7393215.

cranks 15 are swung forwardly, the typebars' are swung up toward the platen.

The cams are controlled, respectively, bythe ke s 18 of the machine, which are arrange in the usual manner on key-levers. Two sets of key-levers are used, half the levers 19 being mounted on a rearwardly located pivot-rod 20, while the other key-levers 21 are pivoted on a forwardly located pivot-rod 22.

Each cam v6 or 7 is formed with an increasingv radius through a little more than 90" of angle. As shown in the drawings, the cam is formed of a single piece of sheet.1 metal, stamped into form to provide a web' portion 23 and an oise't flange 24, and the flange is grooved transversely to form teeth or serrations adapted to prevent slippage of the cam iniengagement with the power-v roller. The cam has a hub 25 which turns on a stationary pivot-pin 26. The cam-lever 8 consists of two parallel sheet-metal members, and the ends of the pivot 26 are fixed therein. A spring 27 is coiled around the hub 25, and one end engages the cam, while the other end of the spring engages a stoppin 28 fixed between the two levermembers. The spring tends to turn the cam in a counter-clockwise direction, and this turning movement is arrested bythe engagement of the Stop-pin with the edge of the cam, as shown in Fig. 1. This figure shows thenormal or inactive position of the parts, wherein the surface of the cam is just clear ofengagement with the ower-roller. l

The key-lever 19 las a depending arm 29 a trip-lever 30. This lever comprises a'strip of sheet-metal with two lugs embracing the arm 29 and connected thereto by a pivot 31. The lower end of the trip-lever lies just above a shoulder 32 on the edge of the cam.l When it iS desired to throw the cam into operation', and the key-lever is 'depressed for this purpose, the trip-lever pushes against the shoulder andr thus imparts a slight rotation to the cam.r The form of the4 cam is such that this causes it to engage the surface ofv the powerroller, whereupon the cam is at once turned through a 'quarter rotation and the bellcrank is moved'to the position shown in Fig.

v3', thus actuating the type-bar connected of the operation of the cam, the type-bar tends to overrun the cam-mechanism, and thus to swing the bell-crank sufliciently to disengage the cam from the'rollen Immediately upon this occurrence they spring27 swings the cam back to its normal position, this action taking place much more quickly than the cam-lever can follow it up in consequence of the return of the type-bar.

During the return movement yof the cam it is necessaryvv that the trip-lever 30 be held out of the path of movement of the shoulder 32, in case the operator continues to hold the key depressed at this time. This is accomplished by means of a trip-pin 34 iXe'd between the arms of the cam-lever. This pin engages an inclined portion 35 of the triplever, and when the cam-lever is swung into the 4position of Fig. 3 the trip-lever is thereby swung well back from the path of the shoulder 32. Upon the return of the eamlever to normal position the trip-lever is allowed to swing back towards the cam.

Since the cam has already returned to normal position, the trip-lever will rest against the end of the shoulder until the key-lever is permitted to rise again and thus raise the trip-lever clear above the shoulder. When this occurs, a spring 33 attached to the upper end of the trip-lever will swing it back into the position of Fig. 1.

The construction and operation of the members co-operating with the cams 7 lare similar to those just described, with the eX- ception, however, that in this case the directions of motion are reversed. The triplever is therefore provided with a hooked lower end to engage the shoulder of the cam, and a stop-pin 37, located above the axis of the cam is used. The key-lever 21 is so arranged .that its rear end rises when the key is depressed, thus raising the trip-lever instead of depressin it.

The invention e aimed is l. Power-mechanism comprising: a constantly driven power-roller; a cam-actuated member; a cam pivoted thereon and adapted for rolling engagement with the powerroller; means for imparting a `forward swinging movement to the cam, upon its pivot, to cause it to engage the roller; and spring-means tending constantly to Swing the cam in the reverse direction.

2. Power-mechanism comprising: a constantly driven power-roller; a cam-lever; a segmental cam pivoted on the cam-lever; key-operated means for imparting a forward swinging movement to the cam to cause it to engagethe roller; and spring-means to'swing the cam in the reverse direction upon disengagement with the roller.

3. Power-mechanism comprising: a constantly driven power-roller; a cam-lever; a segmental cam pivoted on the cam-lever and provided with an abutment; an actuating member adapted to engage .said abutment and impart a forward swingingA movement to the cam to cause it to engage the roller;

a spring for swinging the 'cam reversely when disengaged from the roller; and means for holding the actuating-member out of the path of the abutm'ent during reverse movement of the cam.

4. Power-mechanism comprising: a constantly driven power-roller; a cam-lever comprising' two arms lying side-by-side; a segmental cam pivotally mounted between said arms and provided with a rearwardly projecting abutment; a key-lever; an actuating-lever pivoted to the key-lever and de'- pending therefrom in position to engage and push against said abutment when the keylever is actuated, whereby a forward swinging movement is imparted to the cam; and a spring for swinging the cam reversely; the cam-lever and the actuating-lever having interengaging members whereby said lever is swung out of the path of said abutment when the cam-lever is actuated by engagement of the cam with the power-roller.

FARNUM F. DORSEY. 

